Fluid jet modulated hydraulic governor



Nov. 30, 1965 K. MEHTA 3,220,427

FLUID JET MODULATED HYDRAULIC GOVERNOR Filed July 23, 1962 4 Sheets-Sheet 1 INVENTOR Kuldip Mehfo ATTORNEY Nov. 30, 1965 K. MEHTA 3, 20 4 1 FLUID JET MODULATED HYDRAULIC GOVERNOR Filed July 23, 1962 4 Sheets-Sheet 2 INVENTOR Kuldip Mehfo QKL ZD ATTORNEY Nov. 30, 1965 K. MEHTA 3,220,427

FLUID JET MODULATED HYDRAULIC GOVERNOR Filed July 23, 1962 4 Sheets-Sheet 5 llh i A y 82 so 6 76 Willi"! 98 1 F i 2 96 M m 90 INVENTOR Kuldip Mehfc ATTORNEY Nov. 30, 1965 K. MEHTA 3,220,427

FLUID JET MODULATED HYDRAULIC GOVERNOR Filed July 25, 1962 4 Sheets-Sheet 4 llillll? ATTORNEY United States Patent 3,220,427 FLUID JET MODULATED HYDRAULIC GOVERNOR Kuldip Mehta, New Alipore, Calcutta, West Bengal, India, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed July 23, 1962, Ser. No. 211,633 17 Claims. (Cl. 137-56) My invention relates in general to an improvement in hydraulic governors. More particularly, it is concerned with controlling the operating characteristics of a centrifugal force actuated valve. 7

This invention generally concerns the effecting of improvements in governor controlled units as used in overspeed control systems in conjunction with internal combustion engines, or the like, wherein an engine developed fluid pressure is regulatively applied through a speed-responsive valve to a pressure-responsive servomotor that is in turn operatively connected to adjust an engine throttle in accordance with engine speed.

In conventional centrifugal governor control valve structures, as incorporated in hydraulic governors, the control valve is usually carried by a governor shaft, which may be integral with an engine driven shaft or a separable part, rotatively driven by the shaft of an engine accessory such as the engine distributor. These governor installations have resulted in constructions wherein it is necessary to disassemble the accessory in order to adjust or calibrate the speed setting.

Another problem encountered with prior devices is the effect upon the centrifugal governor control valve when the sensed engine fluid pressure decreases as continued use necessarily results in wear and a reduction in efficiency of the particular pressurizing means. These devices rely upon a relatively high controlling fluid pressure and this decrease materially affects governor control valve response to the extent that prohibitive engine speed often occurs.

In configurations where engine oil pressure is utilized to activate the governor control valve, tests have shown that the oil pump discharge pressure is in the vicinity of 60 pounds per square inch when first put into operation, and after continued use and resultant wear upon the pump this pressure will probably drop to a magnitude of approximately 40 pounds per square inch. This reduction in pressure applied to the centrifugally operated governor control valve results in slower valve response, which often is evidenced by over-speeds in a range of approximately 200 rpm. during acceleration from idle to maximum throttle settings. This overspeed condition is particularly prevalent in an hydraulic governor of the type which relies upon a completely opened valve position during the early phase of engine acceleration to initially charge a line to a fluid motor which controls the throttle setting. More specifically, a lower pressure control fluid requires more time to initially charge the lines between the fluid motor and the governor, and necessarily results in slower governor response.

Accordingly, it is the primary object of this invention to provide a novel construction for a governor control unit wherein a centrifugal force actuated valve is jet modulated by a velocity head of fluid converted from a pressure head of fluid to afford advantageous operating characteristics.

Another object is the provision of a governor control unit employing a fluid jet modulated centrifugal valve that provides a predetermined response rate as desired in a particular application.

A further object is to adapt an existing engine accessory,

.such as an engine oil pump, to accommodate a governor control unit of this type in a manner that extensive modition of the governor unit is not required.

3,220,427 Patented Nov. 30, 1965 A further object of this invention is to provide an hydraulic governor assembly comprising a centrifugal force actuated valve which is responsive to engine speed and yet has the inherent ability to positively charge the lines between the governor unit and a fluid motor, regardless of the pressure of the fluid being supplied to actuate the throttle controlling motor.

Other objects are to provide an improved hydraulic overspeed governor which is of simple and inexpensive construction, which is positive and reliable in operation independent of the magnitude of the pressure fluid utilized in the system, which employs a minimum number of parts and is possessed with stable operating characteristics over a wide range of operating conditions.

FIGURE 1 is a front elevation view of the hydraulic governor assembled to an engine lubricating oil pump and connected to a fluid actuated throttle controlling motor with parts broken away and in section further showing the governor;

FIGURE 2 is a fragmentary side elevation view with parts broken away and in section illustrating the governor adaptor installed on the engine lubricating pump of FIG- URE 1;

FIGURE 3 is a bottom plan view with parts broken away and in section of FIGURE 2;

FIGURE 4 is a sectional view showing a slight modification of the governor assembly shown in FIGURE 1;

FIGURE 5 is a sectional view illustrating a modification of the invention shown in FIGURE 4;

FIGURE 6 is a sectional view illustrating a further modification of this invention;

FIGURE 7 is a sectional view showing a modification of the invention illustrated in FIGURE 6.

Referring now to the drawings, the present invention is shown in assembly in FIGURE 1 wherein an hydraulic governor assembly 2 is secured to a conventional engine lubricating oil pump 4 and is capable of discharging oil under pressure through a line 6 to a pressure responsive fluid motor 8 that is in turn connected to the engine throttle. The fluid motor 8 may be mounted on a wall 10 of the engine crankcase 12, and an oil pan 14 is pro vided to encase the oil pump and governor assembly and provide a sump 16 to provide an intake source for the oil pump.

The lubricating oil pump 4 is mounted in opening 18in the engine crankcase and comprises a pump chamber 20 which contains an axially extending pump shaft 22 having a driver gear 24 secured thereto which meshes with and drives an idler gear mounted on a stub shaft, neither of which is shown, in pump housing 26. The shaft 22 extends axially through the pump housing 26 and is-rotatably supported therein. It is adapted to be driven at'its upper end from a gear on a camshaft within the engine crankcase.

A pump cover 28 .is secured to the pump housing and comprises downwardly extending spaced members or legs 30 and 32 which support the governor unit and an integrally formed, L-shaped intake conduit 34 that connects the low or inlet pressure side of the pump with a strainer 36 in sump 16.

The pump shaft 22 extends through the pump cover 28 and has an end 38 of a reduced diameter, as shown in FIGURE 1. Passages 4t) and 42 are provided so that pressurized oil may be directed through the end of the reduced portion 38 of the shaft.

The governor assembly comprises a housing 44 including an adaptor or support plate 46, a governor shaft portion or governor element 48, and a centrifugally unbalanced control valve assembly carried by the governor shaft. The governor adaptor plate 46 is a onepiece casting having a plurality of upwardly extending bosses 52, 54 and 56, which are adapted to be aligned with the legs and 32 of the pump cover 28 and are detachably secured thereto by bolts 58. The intermediate adaptor plate boss 54, disposed between the aforemen-. tioned bosses, is axially aligned with the pump shaft 22 and contains a bushing 60 which provides a journal for supporting one end of the rotatable governor shaft portion or element 48. The governor element 48 comprises an enlarged portion 62 at its opposite or upper end that is axially bored to receive the pump shaft extension therein. The reduced portion 38 of the pump shaft can be separably drivingly connected to the upper portion of the governor shaft element 48 in any known manner, such as by a spline connection. The governor shaft or rotatable speed responsive governor element 48 has a diametrically extending cross bore 64 intermediate its ends and contains a plurality of staggered fluid passages branching from the cross bore 64 including a pressure inlet passage 66 which communicates with the passage 42 below the reduced end 38 of the pump shaft. A relief passage 68 and a longitudinally extending outlet passage 70 are provided in the lower portion of the rotatable governor element. A transverse or lateral passage 72 is provided in the rotatable governor element 48 to connect with inlet passage 66 and is positioned to convert a head of inlet passage oil pressure to a velocity head and to discharge oil converted to a velocity head in a plane generally perpendicular to the longitudinal axis L of the governor element.

The control valve assembly 58 comprises a spool valve 74, a centrifugal control weight or flyweight 76, a balance spring 78 and a washer-like element 80, shown in FIGURES 4 and 5, that is secured to the valve by a nut 82. The valve 74 has lands 84 and 86 and is slidably fitted in the cross bore 64 in the governor element 48 and has .an annular groove 88 between the ends thereof which serves to establish communication between outlet passage 70 and relief passage 68, the inlet passage 66 and the outlet passage 70, or all three of these passages, depending upon its position as determined in accordance with engine speed.

The counterweight 76 is bored at 90 to be slidably fitted upon the valve member 74, as illustrated in FIGURES 4 and 5. The counterweight 76 is retained upon the valve by means of bolt 92 and washer 94 or by any other known means. 78 seats against a spot face 96 on the governor element 48, and is retained upon the valve by means of nut 82 which threadedly engages a portion 98 of the valve.

A pump discharge passage 100 is provided in the governor adaptor plate 46 and a nipple 102 is received within the adaptor plate 46 and leg 30 of the pump cover 28 to provide a fluid-tight connection to a passage 104 in leg 30, which in turn directs the oil to a fitting 106 in the pump cover 28 so that it may be discharged through line 6 to the fluid motor 8. The fluid motor 8 may be of conventional design and for purposes of illustration in FIGURE 1 comprises a diaphragm 108 which receives pressurized oil on one side and can be vented to the atmosphere on the other side. Also, the fluid motor 8 is shown as being mounted interiorly of the engine wall 10 but could be mounted at any suitable place near the throttle control so as to be connected to the throttle by any suitable mehcanism.

The weight of the governor counterweight 76, the adjusted compressive strength of the valve tensioning spring 78, and the speed of revolution of the governor element 48 determine the extent that the valve 74 moves to govern the flow of fluid under pressure from the oil pump to the pressure responsive motor.

In operation of the device, with the parts of the control system in. a normal position, starting of the engine causes rotation of the pump shaft 22, thereby providing engine lubricating oil under pressure to the hydraulic path or circuit from the pressure side of the pump through the passages and 42. The pressurized oil then passes The valve tensioning spring through the passage 66 in the governor element where it encounters control valve 74 and is regulated thereby. With the valve in the normal position, the annular groove 88 in the approximate middle thereof is in registry with the pressure relief slot or passage 68 and the pressure fluid outlet branch passage 70 so as to relieve the fluid pressure on the motor 8.

As the engine speed increases, the speed of the pump shaft 22 rotates the governor element 48 and the counterweight 76 causes the valve to move radially outwardly of the governor element against the force of spring 78. The spool valve groove 88 is initially moved into momentary registry with the inner end of all three passages 66, 68 and 70 in the governor element and then, after passing through an intermediate position, is finally moved to regulate the pressure fluid between the inlet and outlet passages, causing substantially all or full lubricating oil pressure to be applied to the fluid motor 8 in accordance with the prevailing engine speed. It is significant that the valve is momentarily in registration with all three of the passages, as this feature limits a sudden application of pressure to the fluid motor and in this manner prevents overshooting or overrunning of the engine as well as consequent hunting that would otherwise exist.

Movement of the valve to the previously mentioned intermediate position affords application of full pump discharge pressure through the valve 74 to the passages 70, and 104, and through line 6 to the fluid motor 8 so that these lines are initially charged with pressure fluid prior to the governing operation of the system. A further increase of engine speedthen moves land 84 of the valve to a position where it partially blocks the outlet passage 70 in the governor element and thereby regulates the amount of pressure fluid applied to the fluid motor to limit maximum operating conditions as desired.

With reference to FIGURE 1, the lateral passage 72 in the governor element, upstream of the control valve, provides a feature heretofore unknown in this art. This passage, because of its specifically designed size, converts a predetermined quantity of fluid in passage 66 from a pressure head to a velocity head and sprays this predetermined quantity of oil having the converted velocity head against a member, such as nut 82, which is secured to one end of valve 74. This discharging of fluid against nut 82 or washer-like baffle element 80 shown in FIG- URES 4 and 5 results in an impact force determined by the fluid mass and its velocity head which deters rapid movement of the valve to the governor or speed regulating position and in this manner guarantees full charging of the lines downstream of the valve to the fluid motor, which is essential to desirable responsive operation of the motor. Tests have shown that this improved governor reduces overspeed to a quantity in the vicinity of 25 rpm, while a device such as that shown in Kennedy 2,756,305 often results in overspeeds in the range of approximately 200 r.p.m. The spraying of this predetermined quantity of oil against the baflie or washer-like element 80, which could be an integral shoulder formed on the valve member 74, is predesigned. such that it will allow the valve to reach a governing position simultaneously with the filling or charging ofthe passages downstream of the, valve.

Referring now to FIGURE 5, a modification of the subject device is shown incorporating laterally extending passages 110 upstream of the valve 74 in the governor element 48. Passages 110 convert a pressure head of fluid to a velocity head and are positioned to direct a predetermined quantity of converted velocity head fluid against the, centrifugal weight 76, thereby accelerating movement of the valve to its governing position and providing a faster valve response. This configuration may be necessary in systems where charging of the lines downstream of the valve in a fluid motor is not critical and it is desired to place the valve in a governing position immediately upon an engine speed change.

FIGURE 6 illustrates a further modification of the subject governor unit in which the valve member 74 is provided with a passage 112 extending for a partial longitudinal distance therethrough and is designed to receive fluid through a transverse valve passage 113. Passage 112 converts a predetermined quantity of fluid from passage 113 from a pressure head to a velocity head in a direction along the axis of reciprocation of valve member 74, and discharges the predetermined quantity of velocity head oil at the spring end of the valve such that the force created by the acceleration of the fluid mass in converting it from a pressure head to a velocity head reacts against the valve member in a direction along the axis of valve reciprocation and opposite to the fluid acceleration direction. This reaction force of the fluid accelerates movement of the valve to its governing position.

With reference to FIGURE 7, the valve 74 is shown to comprise a partial longitudinal passage 114 of a predetermined size which receives fluid through a transverse passage 115 and discharges oil from the valve at the centrifugal weight end through bolt 92 so that the reactive force of the discharging fluid deters movement of the valve while it is tending to move to a governing position. Baflle members 116 can be rigidly secured within a governor housing at either end of the valve so that the fluid discharged from either of the internal passages 112 and 114 in the valve can be sprayed against these members and the movement of the valve in that direction will be braked in a more positive manner due to fluid rebound and reengagement with the valve 74, and the fluid hearing or ground effect as the outer end surface of bolt 92 closely approaches the baffle.

While various. modifications within the spirit of this invention may occur to those skilled in the art, these are contemplated by the inventor to be within the scope of legal protection provided for and limited only by the appended claims.

What is claimed is:

1. An hydraulic governor adapted to be connected to a conventional engine oil pump comprising a housing, an engine driven shaft rotatably received in said housing, a support having a journal in a portion thereof and detachable from said housing, a rotatable governor element having a plurality of passages therein, one end of said rotatable governor element being journaled in said support, a separable rotative drive connection between the other end of said rotatable governor element and said shaft, a centrifugally unbalanced spring biased valve slidably mounted in said rotatable governor element between said passages therein for controlling communication therebetween, a control Weight mounted on one end of said valve, a washer-like element secured to the other end of said valve, and one of said passages in said rotatable governor element being disposed to convert a pressure head of fluid to a velocity head of fluid and transmit a predetermined quantity of fluid converted to a velocity head against said washer-like element to retard movement of said valve during the initial operation of a vehicle engine.

2. An hydraulic governor comprising a housing, an engine driven shaft rotatably mounted in said housing, a rotatable governor element journally supported in said housing and adapted to be connected to said shaft, said rotatable governor element having a plurality of passages therein, a centrifugally unbalanced spring-biased valve slidably mounted in said rotatable governor element be tween the said passages therein for controlling fluid flow therebetween, said valve being spring biased to a first position such that flow through said governor element is blocked, a control weight secured to said valve, a baflle member secured to the other end of said valve, said valve being operable to a second position during initial rotation of said engine driven shaft, and being further operable to a third position in reponse to a higher rate of rotation of said governor member such that said valve controls the amount of fluid passed through said governor member in accordance with a sensed engine speed, and means including a passage in said governor member upstream of said valve for converting a pressure head of fluid to a velocity head of fluid and located so as to direct a predetermined quantity of fluid converted to a velocity head against said baffle member thereby retarding movement of said valve from its initial position during the lower speed ranges of a vehicle engine.

3. An hydraulic governor responsive to engine lubricating oil pressure comprising a housing, a rotatable governor element mounted in said housing and being driven in accordance with engine speed, said governor element having a plurality of passages therein, a control valve mounted in said governor element so as to regulate the rate of engine oil flow therethrough, a spring biased valve slidably supported in said governor element and having a control weight on one end thereof, said valve being biased to a first position to prevent flow of engine oil through said governor element, said control weight affording a centrifugal force suflicient to move said valve against its biasing spring so as to initially completely open the flow through said governor element and being capable of further moving said valve to a governor controlling position so that the quantity of pressure fluid flowing through said valve is in proportion to a sensed engine speed, and a passage in said governor member upstream of said valve for converting a pressure head of fluid to a velocity head of fluid and positioned to direct a predetermined quantity of fluid converted to a velocity head against said control weight so as to accelerate movement of said valve during the initial rotation of said governor member. 4. An hydraulic governor comprising a housing, a governor element rotatably supported Within said housing, said governor element being adapted to be connected with an engine-driven shaft so as to be rotated in accordance with engine speed, a plurality of passages in said governor member, said passages being adapted to receive a pressurized fluid, and a spring biased centifugally unbalanced valve slidably mounted in said governor element such that said valve is displaced from a normal position in response to engine speed, said valve comprising a longitudinal passage extending partially therethrough and adapted to connect with said fluid receiving passages in said governor member and to convert a pressure head of fluid to a velocity head of fluid so that a predetermined quantity of fluid converted to a velocity head is exhausted from an end of said valve to generate a reaction force acting on said valve modifying movement of said valve from its normal position during initial phases of engine operation.

5. An hydraulic governor as described in claim 4 further comprising a baflie member rigidly secured Within said housing member and positioned to receive the fluid flowing from said passage in said valve member and rebound at least a portion of the fluid into impact engagement with said valve member thereby deterring movement of said valve during a portion of its range of movement.

6. In the combination of an engine lubricating oil pump and an hydraulic governor wherein said engine oil pump comprises a housing, an engine driven shaft rotatably mounted in said housing and containing passages adapted to transmit engine oil at pump discharge pressure to said governor member, a governor housing, a rotatable speed responsive governor element journaled in said governor housing, said governor element comprising means adapting it to be fastened to said engine driven shaft, said governor element further having passages therein to afford a transmittal of pressurized oil therethrough, and a springbiased valve slidably mounted in said governor element so as to regulate flow of pressurized oil therethrough, said 7 valve comprising a control weight which results in a displacement of said valve in accordance with centrifugal forces created at particular engine speeds, the improvement comprising a passage means receiving pressurized oil from at least one of said governor element passages and converting the pressure head thereof to a velocity head and directing the velocity head oil against said control weight to accelerate displacement of said valve during low engine speed operation.

7. In combination with an engine accessory having a housing and an engine driven shaft rotatable in the housing, an hydraulic governor assembly comprising a support member, a rotatable governor element having a plurality of passages therein, one of said rotatable governor element being journaled in said support, a separable rotative drive connection between the other end of said rotatable governor element and said shaft, and a centrifugally unbalanced spring-biased valve slidably mounted in said rotatable governor element between the said passages therein for controlling communication therebetween, one of said passages in said rotatable governor element being disposed upstream of said valve member and arranged to convert a predetermined quantity of pressure fluid from a pressure head to a velocity head and direct the velocity head fluid against said valve member so as to deter movement of said valve during low speed engine operation.

8. In an hydraulic governor assembly comprising a housing, a rotatable governor element supported in said housing, one end of said rotatable governor element being adapted for separable connection with an engine driven shaft and having a plurality of passages to receive pressurized engine oil therein, and a control valve slidably mounted within said rotatable governor element, said valve being responsive to applied centrifugal forces and operable to predetermined controlling positions in accordance with a sensed speed; the improvement comprising provision of passage means in said hydraulic governor assembly receiving pressurized engine oil from one of said plurality of passages .and disposed to convert the predetrmined quantity of pressurized engine oil so received from a pressure head to a velocity head to modify movement of said control valve from a normal position.

9. The improved hydraulic governor assembly as defined by claim 8 wherein the improvement further com- 9 prises the provision of said passage means partially J through said valve so that pressurized oil is discharged from one end of said valve thereby deterring movement of the valve from a normal position during the initial phases of engine operation.

10. The improved hydraulic governor assembly as defined by claim 8 wherein the improvement further comprises the providing of said passage means in said control valve partially therethrough so that pressurized oil is discharged from the end of said valve and movement from a normal position is enhanced during low speed engine operation.

11. The improved hydraulic governor assembly as defined by claim 8 wherein the improvement turther comprises the provision of said passage means in said control valve such that pressurized oil is discharged from an end of the valve and a bafiie is secured to said housing so that the discharged oil impinges against said baffle and deters movement of said valve from a normal position during low speed engine operation.

-12. The improved hydraulic governor assembly of claim 8, wherein the improvement further comprises the provision of said passage means so that a force generated by the velocity head oil acts on said valve to retard said valve in movement from its normal position.

13. The improved hydraulic governor assembly of claim 12, said passage means being in said rotatable governor element.

14, The improved hydraulic governor assembly of claim 12, said passage means being in said control valve.

15. The improved hydraulic governor assembly as described in claim 8 wherein the improvement further comprises the placing of said passage means so that a force generated by the velocity head oil acts on said valve so that said valve is accelerated from its normal position during low speed engine operation.

16. The improved hydraulic governor assembly of claim 15, said passage means being in said rotatable governor element.

17. The improved hydraulic governor assembly of claim 15, said passage means being in said control valve.

References Cited by the Examiner UNITED STATES PATENTS 1,811,850 6/1931 Huff 137-56 2,149,645 3/1939 Sittert 13757 X 2,662,795 12/1953 Bartling 13756 X 2,722,205 11/ 1955 Lautzenhiser l3756 X 2,736,305 2/1956 Kennedy 137-56 X 2,741,256 4/1956 Barton 13756 2,840,094 6/1958 Tap'lin 137-56 X ISADOR WEIL, Primary Examiner.

CLARENCE R. GORDON, Examiner. 

8. IN AN HYDRAULIC GOVERNOR ASSEMBLY COMPRISING A HOUSING, A ROTATABLE GOVERNOR ELEMENT SUPPORTED IN SAID HOUSING, ONE END OF SAID ROTATABLE GOVERNOR ELEMENT BEING ADAPTED FOR SEPARATE CONNECTION WITH AN ENGINE DRIVEN SHAFT AND HAVING A PLURALITY OF PASSAGES TO RECEIVE PRESSURIZED ENGINE OIL THEREIN, AND A CONTROL VALVE SLIDABLY MOUNTED WITHIN SAID GOVERNOR ELEMENT, SAID VALVE BEING RESPONSIVE TO APPLIED CENTRIFUGAL FORCES AND OPERABLE TO PREDETERMINED CONTROLLING POSITIONS IN ACCORDANCE WITH A SENSED SPEED; THE IMPROVEMENT COMPRISING PROVISION OF PASSAGE MEANS IN SAID HYDRAULIC GOVERNOR ASSEMBLY RECEIVING PRESSURIZED ENGINE OIL FROM ONE OF SAID PLURALITY OF PASSAGES AND DISPOSED TO CONVERT THE PREDETERMINED QUANTITY OF PRESSURIZED ENGINE OIL SO RECEIVED FROM A PRESSURE HEAD TO A VELOCITY HEAD TO MODIFY MOVEMENT OF SAID CONTROL VALVE FROM A NORMAL POSITION. 